Fire hydrants generally are provided at spaced intervals throughout water line systems of areas having fire protection, such as cities, subdivisions, rural districts, etc. Generally, many of the systems of water lines are subject to becoming infiltrated with foreign matter as a result of water line breakage from such causes as being broken by heavy equipment during construction, or, in rural areas, by a tractor, etc. In such cases, generally before service can be restored, the system must be purged of foreign matter. Generally, this is accomplished by locating the fire hydrant at the end of the water line system and opening the hydrant for flowing water through until the foreign matter, such as mud, etc., is purged from the water lines.
The use of fire hydrants for purging such systems is an expensive undertaking. First of all, typical fire hydrants are expensive. Secondly, the use of such expensive hydrants requires wear and tear on the working parts of the hydrant in a purging operation when the use of the hydrant should be restricted to its intended purpose, i.e., for fighting fires.
Typically, fire hydrants (such as the American-Darling valve, a division of American Cast Iron Company) include a barrel having a nozzle at its upper end and a base at its lower end. A globe valve is mounted in a seat carried in the base. The valve includes a valve top, bottom, and a special hydrant valve rubber of conical shape. A valve rod is screwed into the valve base and extends upwardly and through the top cover of the hydrant assembly. A hydrant seat is threadably secured in the barrel assembly and includes drain channels for draining water from the barrel after the hydrant has been used and the valve closed. A spring biased drain lever is provided with washers thereon to seal the drain channels during use of the hydrant.
Each time such fire hydrants are used, the globe valve in the hydrant is turned many times against the valve seat in frictional engagement therewith. Such frictional engagement, of course, causes substantial wear and tear on the parts. The drain lever washers also receive unneeded wear by coming into engagement with the surfaces around the drain channels.
One way of reducing the wear and tear of the hydrant operating parts is to eliminate the use of fire hydrants for such secondary functions as purging water lines of foreign matter, or, in sme cases, stagnant water, etc. This may be accomplished by providing separate, inexpensive flush hydrants at strategic locations of a water line system, such as at the end of a water line system of a subdivision.
Such flush hydrants must be dependable and inexpensive. To this end, applicant has provided a flush hydrant having a ball valve assembly therein which uses a ball closure member to perform the dual function of controlling flow through the valve body and draining the water from the barrel of the hydrant assembly after flow through the valve body has been stopped. This is accomplished in applicant's structure without the need of the three-piece globe valve, the expensive hydrant seat with its drain ports therein, and the drain lever and washers carried by the drain lever for closing the drain channel. Also, the need of a spring for biasing the drain lever downwardly for engagement of the washers with the drain ports is eliminated.